package payment

import (
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"

	"git.linuxforward.com/byom/byom-onboard/internal/platform/mailer"
	"github.com/gin-gonic/gin"
	"github.com/stripe/stripe-go/v81"
	"github.com/stripe/stripe-go/v81/account"
	portalsession "github.com/stripe/stripe-go/v81/billingportal/session"
	"github.com/stripe/stripe-go/v81/checkout/session"
	"github.com/stripe/stripe-go/v81/webhook"
)

type StripeHandler struct {
	domain         string
	endpointSecret string
	mailer         *mailer.Mailer
}

func NewStripeHandler(apiKey, endpointSecret, domain string, mailer *mailer.Mailer) (*StripeHandler, error) {
	stripe.Key = apiKey

	// Test connection by retrieving account information
	_, err := account.Get()
	if err != nil {
		return nil, fmt.Errorf("failed to connect to Stripe: %w", err)
	}

	return &StripeHandler{
		domain:         domain,
		endpointSecret: endpointSecret,
		mailer:         mailer,
	}, nil
}

func (h *StripeHandler) CreateCheckoutSession(c *gin.Context) {
	// Get email from request
	customerEmail := c.PostForm("email")
	if customerEmail == "" {
		c.JSON(http.StatusBadRequest, gin.H{"error": "Email is required"})
		return
	}

	checkoutParams := &stripe.CheckoutSessionParams{
		Mode: stripe.String(string(stripe.CheckoutSessionModePayment)),
		LineItems: []*stripe.CheckoutSessionLineItemParams{
			{
				PriceData: &stripe.CheckoutSessionLineItemPriceDataParams{
					Currency: stripe.String("eur"),
					ProductData: &stripe.CheckoutSessionLineItemPriceDataProductDataParams{
						Name: stripe.String("Byom Subscription"),
					},
					UnitAmount: stripe.Int64(2000), // 20€ en centimes
				},
				Quantity: stripe.Int64(1),
			},
		},
		SuccessURL:       stripe.String("http://192.168.1.35:5173/payment/success?session_id={CHECKOUT_SESSION_ID}"),
		CancelURL:        stripe.String("http://192.168.1.35:5173/payment/cancel"),
		CustomerEmail:    stripe.String(customerEmail),
		CustomerCreation: stripe.String(string(stripe.CheckoutSessionCustomerCreationAlways)),
	}

	s, err := session.New(checkoutParams)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	// Renvoyer uniquement l'URL et l'ID de session
	c.JSON(http.StatusOK, gin.H{
		"url":       s.URL,
		"sessionId": s.ID,
	})
}

func (h *StripeHandler) CreatePortalSession(c *gin.Context) {
	sessionID := c.PostForm("session_id")

	s, err := session.Get(sessionID, nil)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		log.Printf("session.Get: %v", err)
		return
	}

	params := &stripe.BillingPortalSessionParams{
		Customer:  stripe.String(s.Customer.ID),
		ReturnURL: stripe.String(h.domain),
	}
	ps, err := portalsession.New(params)
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		log.Printf("ps.New: %v", err)
		return
	}

	c.Redirect(http.StatusSeeOther, ps.URL)
}

func (h *StripeHandler) HandleWebhook(c *gin.Context) {
	const MaxBodyBytes = int64(65536)
	bodyReader := http.MaxBytesReader(c.Writer, c.Request.Body, MaxBodyBytes)
	payload, err := io.ReadAll(bodyReader)
	if err != nil {
		log.Printf("[Webhook Debug] Error reading body: %v", err)
		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "Service unavailable"})
		return
	}

	log.Printf("[Webhook Debug] Received payload: %s", string(payload))

	signatureHeader := c.Request.Header.Get("Stripe-Signature")
	log.Printf("[Webhook Debug] Stripe-Signature header: %s", signatureHeader)
	log.Printf("[Webhook Debug] Using endpoint secret: %s", h.endpointSecret)

	event, err := webhook.ConstructEvent(payload, signatureHeader, h.endpointSecret)
	if err != nil {
		log.Printf("[Webhook Debug] Signature verification failed: %v", err)
		log.Printf("[Webhook Debug] Headers received: %+v", c.Request.Header)
		c.JSON(http.StatusBadRequest, gin.H{"error": "Bad request"})
		return
	}

	log.Printf("[Webhook Debug] Event type received: %s", event.Type)
	log.Printf("[Webhook Debug] Event data: %s", string(event.Data.Raw))

	switch event.Type {
	case "customer.subscription.deleted":
		var subscription stripe.Subscription
		if err := json.Unmarshal(event.Data.Raw, &subscription); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		log.Printf("Subscription deleted for %s.", subscription.ID)

	case "customer.subscription.updated":
		var subscription stripe.Subscription
		if err := json.Unmarshal(event.Data.Raw, &subscription); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		log.Printf("Subscription updated for %s.", subscription.ID)

	case "customer.subscription.created":
		var subscription stripe.Subscription
		if err := json.Unmarshal(event.Data.Raw, &subscription); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		log.Printf("Subscription created for %s.", subscription.ID)

	case "checkout.session.completed":
		var session stripe.CheckoutSession
		if err := json.Unmarshal(event.Data.Raw, &session); err != nil {
			log.Printf("[Webhook Debug] Failed to parse session data: %v", err)
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		log.Printf("[Webhook Debug] Payment successful for session: %s", session.ID)

		customerEmail := session.CustomerEmail
		log.Printf("[Webhook Debug] Customer email: %s", customerEmail)

		if err := h.mailer.SendWelcomeEmail(customerEmail, &mailer.EmailData{
			Username:   customerEmail,
			WebAppURL:  fmt.Sprintf("http://test.byom.fr/login?email=%s", customerEmail),
			SetupGuide: "Votre espace de travail est prêt ! Connectez-vous pour commencer à utiliser Byom.",
		}); err != nil {
			log.Printf("[Webhook Debug] Failed to send welcome email: %v", err)
		}

	case "checkout.session.expired":
		var session stripe.CheckoutSession
		if err := json.Unmarshal(event.Data.Raw, &session); err != nil {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		log.Printf("Payment session expired: %s", session.ID)
		// TODO: Gérer l'expiration de la session

	default:
		fmt.Fprintf(os.Stderr, "Unhandled event type: %s\n", event.Type)
	}

	c.JSON(http.StatusOK, gin.H{"status": "success"})
}